diff options
| -rw-r--r-- | source/slang/slang-ir-simplify-cfg.cpp | 11 | ||||
| -rw-r--r-- | tests/bugs/gh-6860.slang | 20 | ||||
| -rw-r--r-- | tests/bugs/gh-6862.slang | 29 |
3 files changed, 56 insertions, 4 deletions
diff --git a/source/slang/slang-ir-simplify-cfg.cpp b/source/slang/slang-ir-simplify-cfg.cpp index 280874f74..2310a5cce 100644 --- a/source/slang/slang-ir-simplify-cfg.cpp +++ b/source/slang/slang-ir-simplify-cfg.cpp @@ -728,9 +728,9 @@ static bool simplifyBoolPhiParams(IRBlock* block) static bool removeTrivialPhiParams(IRBlock* block) { - // We can remove a phi parmeter if: - // 1. all arguments to a parameter is the same (not really a phi). - // 2. the arguments to the parameter is always the same as arguments to another existing + // We can remove a phi parameter if: + // 1. all non-self-referential arguments to a parameter are the same (not really a phi). + // 2. the arguments to the parameter are always the same as arguments to another existing // parameter (duplicate phi). bool changed = false; @@ -765,7 +765,10 @@ static bool removeTrivialPhiParams(IRBlock* block) termInsts.add(termInst); for (UInt i = 0; i < termInst->getArgCount(); i++) { - if (args[i].areKnownValueSame) + // Self-referential parameters can be skipped, as they cannot + // introduce a new value. The phi can only have multiple different + // values if non-self-referential arguments differ. + if (args[i].areKnownValueSame && termInst->getArg(i) != params[i]) { if (args[i].knownValue == nullptr) args[i].knownValue = termInst->getArg(i); diff --git a/tests/bugs/gh-6860.slang b/tests/bugs/gh-6860.slang new file mode 100644 index 000000000..13a7e329a --- /dev/null +++ b/tests/bugs/gh-6860.slang @@ -0,0 +1,20 @@ +//TEST:SIMPLE(filecheck=CHECK): -target spirv +// CHECK: OpEntryPoint +func breaker()->float { + var x: float; + for (int i = 0; i < 1; ++i) { + if (true) { + } else { + x = 0.0; + } + } + return x; +} + +[shader("fragment")] +float4 fragment(float4 in: SV_Position) + : SV_Target +{ + let res = breaker(); + return float4(0, 0, 0, 0); +} diff --git a/tests/bugs/gh-6862.slang b/tests/bugs/gh-6862.slang new file mode 100644 index 000000000..8b65b2f2a --- /dev/null +++ b/tests/bugs/gh-6862.slang @@ -0,0 +1,29 @@ +//TEST:SIMPLE(filecheck=CHECK):-stage fragment -entry fragment -target wgsl + +func dummy(b: StructuredBuffer<float>)->float { + return 0; +} + +func breaker(b: StructuredBuffer<float>)->float { + // CHECK-NOT: var<storage, read> {{.*}} : array<f32> = {{.*}}; + var x: float = 0; + for (int i = 0; i < 1; ++i) { + x = dummy(b); + if (true) { + } else { + return 0; + x = 0; + } + } + return x; +} + +StructuredBuffer<float> b; + +[shader("fragment")] +float4 fragment(float4 in: SV_Position) + : SV_Target +{ + let res = breaker(b); + return float4(res, 0, 0, 0); +} |